Preheat the Griddle: Heat your Blackstone griddle to medium-high heat for 5 minutes. Lightly oil the surface with sesame oil.
Cook the Chicken and Steak: Add sesame oil to the griddle and place the cubed chicken and sliced steak separately on the surface.Season with soy sauce, garlic, salt, and pepper.Cook chicken for 6-7 minutes, flipping occasionally, until golden and cooked through. Sear steak slices for 3-4 minutes per side, adjusting for your desired doneness. Move to the side.
Sauté the Vegetables: Add olive oil and cook the zucchini, mushrooms, onions, and carrots on the griddle.Season with soy sauce and stir frequently for 4-5 minutes until tender but crisp. Push to the side.
Prepare the Fried Rice: Melt butter and spread day-old rice evenly over the griddle.Create a small well in the rice, pour in beaten eggs, and scramble until cooked.Mix the eggs into the rice, then add peas, carrots, soy sauce, and sesame oil. Stir and fry for 3-4 minutes.
Combine and Serve: Mix chicken, steak, vegetables, and fried rice together. Let cook for 2 more minutes to combine flavors. Serve hot with additional soy sauce or garlic butter if desired.